Road-roller.



K. ZAWADZINSKI.

ROAD 'ROLLER.

APPLICATION FILED JUNE 30, 1913.

1,088,509 Patented Feb. 24, 1914.

KAZIMIERZ ZAWAIDZINSKI, or wanowron, AUSTRIA-HUNGARY.

ROAD-ROLLER.

Specification of Letters Patent.

Patented Feb. 4, 1914..

Application filed June 30, 1913. Serial No. 776,712.

b all whom it may concern Be it known that I, Kaznrmnz ZA\VADZIN ski, asubject of the iiustro-Hungarian Emperor, and residing at l l adowice,G-alicia, AustriaHungary, have invented certain new and usefulImprovements in Road-Rollers, of which the following is a specification.

My invention relates to road rollers.

Road rollers heretofore in general use i. 6. both horserollers andsteam-rollers, have the defect that the specific pressure applied to thesurface of the road-facing can be varied only within small limits. Thisis because changes in the specific pressure of such rollers are made byi creasing the weight of the roller, this being generally effected inthe case of horse-rollers by means of sand or water, and in the case ofsteamrollers by blocks of iron. An increase in specific pressure whichis brought about by an increase in weight, however, permits gradualcompression of the road-facing only to a limited extent, because theserollers can exert pressure only on a supporting surface of constantarea, and the specific pressure can be increased only so far as ispermitted by the weight added to the roller and so far as this addedweight can come wholly into operation per unit area. In the case ofhorse-rollers, the added weight is limited by the power of the horse.For this reason the weight of this type of roller is at most 10 tons. Toobtain a greater specific load on the road-facing to be rolled,steam-rollers are therefore employed, the weight of which may indeedamount to 20.tons. This type of roller has, however, the disadvantagethat the weight can be increased to a much smaller extent than in thecase of horse-rollers, the limitation being due to the necessarily heavyweight of material required for the construction of the steam-rolleritself. Moreover, a steam-roller has the drawback that, owing to thespecific pressure being too great at the beginning of rolling, thisroller cannot exercise a gradual and long-range compression on theroad-facing which is being rolled. The undulations in the gravel, whichare distinctly visible 6. g. in front of the roller, are ample proofthat the facing of gravel, though it has already been somewhatcompressed, is again broken up, to be then crushed and firmlycompressed. In many cases therefore in order to be able successfully toroll the road-facing, the lighter horse-roller has had to be first used,its

weight being gradually increased, and only then could the steam-rollerbe employed. Moreover, the steam-roller is an expensive appliance whichon that account is not accessible to every road-builder. The fuelrequisite therefor as well as the attendants required involve a heavyoutlay. More over, bridges and so on must be built with a view tosupporting the heavy weight of steamrollers, and therefore a greaterweight than would be needed for the normal traffic on the road, wherebythe cost of road building is uselessly increased, the more so as thepassage of such rollers over it frequently necessitates the road beingrepaired from time to time. Further, the method of gradually loading therollers of either of the above-named types by means of blocks of iron,sand and water must likewise be regarded as exceedingly disadvantageous,as these auxiliaries must be always kept at disposal and consequentlyhave to be first conveyed to the spot.

A primary object of my invention is to obviate the above-describeddefects, all of which are well-known to everyone versed in the art. Tothis end, I provide a roller, the novel essential feature of which isthat, while the weight is keptconstant, the specific surface-pressure inthe direction of the thrust is increased or diminished by chang ing thediameter of the roller.

One illustrative embodiment of my invention is represented by way ofexample in the accompanying drawing, wherein Figure 1 is a sectional endelevation, Fig. 52 is a vertical longitudinal section, Fig. 3 an endelevation according to Figs. 1 and 2, and Fig. 4 an end elevationshowing the roller when one of the smaller auxiliary rollers is inoperation.

As is well known, the specific surface-pressure of a roller is dependenton the weight of the roller and the area of the supporting surface. Thelatter again depends not only on the width of the roller and theelasticity of the materials on which it rests but also on the diameterof the roller. If therefore a high specific surface-pressure of theroller is desired, it suffices, instead of increasing the weight of theroller, to keep the weight constant and reduce the diameter. In theexample illustrated, the reduction of the diameter of the roller isobtained owing to the complete device comprising two, three or morerollers, of which the largest incloses the others, and the latter servethen as weights. The rollers are so arranged that it is possible to rollby means of each of them, the entire weight of the complete clevicebeing transmitted to the working roller.

Referring to the drawing, (6 represents the main cram or iron rollerhaving dimensions corresponding to those of the ordinary horseroller;Z), 0 represent two auxiliary rollers, the diameter of which is smallerthan that of the main roller a. The appliance is so designed that theauxiliary rollers do not hinder the action of the main roller at, theseauxiliary rollers being located inside the latter. The number ofauxiliary rollers may of course be as large as desired provided that thechamber in the main roller can contain them, it being manifestlydesirable to increase the specific load applied to the ground gradually,2'. e. in as many stages as possible. The auxiliary rollers mounted inthe said chamber must however, on practical grounds, be so distributed,and the weight of the same be so chosen, that when roller a is working,the center of gravity of the complete device is located in the axis ofthis roller because, if not, disturbances due to the want of balancewould arise, which would have a detrimental influence both on theworking of the roller and on the draft-animal or drivingengine.

The roller a may be provided either with a shaft extending axiallythroughout its length, or, as in Figs. 1 and 2, be journaled by means ofpins 0 in bearings (Z, which are integral with the frame 6. The portionsf, g of the crown of the roller a, which are located outside theauxiliary rollers, can be removed in order to allow the auxiliaryrollers to project beyond the peripheral surface of the roller a (Fig.4).

After, for example, the gravel facing of the road has been compressed bythe main roller a, a change is made whereby the next smaller roller, 6in Fig. 1, is put into operation. The latter roller is journaled in theend walls of the roller a, so as to be transversely slidable therein, itbeing possible for these end walls to have spokes because there is noneed to seal the inner chamber of the roller a. The bearings whichjournal the roller Z) are slidable in elongated apertures h and can bedisplaced such a distance that the auxiliary roller b projects beyondthe crown of the roller a, where it is held in position by means of keysor wedges z'. No difliculty arises in changing the position of theauxiliary roller. The auxiliary roller 6 being at the top, the key 2' iswithdrawn, and when the roller a is again rotated the auxiliary roller 5falls by gravity as far outward as the ap rture it permits. The key isthereupon again put into place, but now on the other side of the bearingis.

When the roller a is still further rotated the weight of the entiredevice is borne by the roller 7). \Vhen this position is obtained, theroller (4 must be held fast. This is effected in simple manner byinserting keys into the holes at which are suitably located in the endwalls of the main roller a.

The keys hear at their projecting ends against the frame 6 and preventthe roller a rotating, so that now only the auxiliary roller Z) does therolling work. As Figs. 3 and a show, several of such holes arepreferably provided, so that the center of gravity of the entire devicecan be removed from the point of support of the auxiliary roller 7) inone direction or the other, in order to thus obtain stable balance withthe aid of the second point of support which is furnished by the frameand the horses therein. After the roller 6 has been used for rolling forthe necessary length of time,

the roller 0 with a still smaller diame;er can be similarly brought intoaction, the roller Z) being then pushed back.

The abovedescribed road-roller admits of the employment of a brakingdevice of any suitable construction both for the main roller as well asfor the auxiliary rollers, and either the crowns or the end walls of therollers may be used for the purpose. Scrapers can also be arranged inany suit able manner. The attendance required for my new device involveslittle time and at most the employment of two men, so that expenses inthis respect are reduced to a minimum. Finally it may be pointed outthat the smaller width of the auxiliary rollers serves to still furtherincrease the specific load. Moreover, this device is suitable for beingdriven in any manner, whether by horse, by steam-engine or bypetrol-engine; in the two latter cases the motion of the engine can beimparted by suitable transmission means to the axle of the operativeroller after adjustment of the latter. Both the dimensions and weight ofthe device can be chosen within desired limits to suit the purpose ofemployment and the tractive force at disposal.

I claim 1. In a road roller, the combination with a frame, of aplurality of rollers progressively increasing in diameter rotatablymounted therein, and means for holding all the rollers but one in aninoperative position.

2. In a road roller, the combination with a frame, of a plurality ofrollers progressively increasing in diameter rotatably .mounted therein,the largest roller normally surrounding the remaining rollers and meansfor holding all the rollers but one in an inoperative position.

3. In a road roller, the combination with a frame, of a plurality ofrollers progressively increasing in diameter rotatably mounted therein,the largest. roller normally surrounding the remaining rollers and meansfor holding all the rollers but one in an inoperative position; thelargest roller having one or more removable portions of its peripheryfor allowing the one or more smaller rollers to project beyond the saidperiphery.

a. In a road roller, the combination with a frame, of a main rollerjournaled therein, said main roller having removable plates in itsperiphery and elongated radial apertures in its end Walls, a pluralityof auxiliary rollers or different diameters j ournaled radiallydisplaceable in said apertures, and keys for holding said auxiliaryrollers in said apertures.

5. In a road roller, the combination With a frame, of a plurality ofrollers progressively increasing in diameter rotatably mounted therein,the largest roller normally surrounding the remaining rollers and meansfor holding all the rollers but one in an in operative position; thelargest roller having one or more removable portions of its peripheryfor allowing the one or more smaller rollers to project beyond the saidperiphery; and means for fastening the largest roller to said frame inpredetermined positions relatively thereto.

6. In a road roller, the combination With a frame, of a plurality ofrollers progressively increasing in diameter rotatably mounted therein,the largest roller normally surrounding the remaining rollers and havinga plurality of stop-holes in its end Wall, and means for holding all therollers but one in an inoperative position; the largest roller havingone or more removable portions of its periphery for allowing the one ormore smaller rollers to project beyond the said periphery; and keysengaging in said holes and bearing against said frame for holding thelargest roller in a predetermined position.

In testimony whereof I EtfllX my signature in presence of two Witnesses.

KAZIMIERZ ZAWADZINSKI.

Witnesses Aueusr FUoenR, ADA MARIA BRYCE.

flopies of this patent may be obtained for five cents each, byaddressing the Commissioner of l atents, Washington, D. G.

